Sore throat, or pharyngitis, causes pain and discomfort in the throat, which makes it painful to swallow food, reports MedlinePlus. Patients may suffer from a sore throat if they have a cold, the flu or the mononucleosis virus. These may cause inflammation in the area at the back of the throat between the larynx and the tonsils. Strep throat is a disease that results from an infection with the group A Streptococcus bacteria, and it often causes sore throats and pain when swallowing.
Sources: healthline.com, nlm.nih.gov, nlm.nih.gov, cancer.org